軌道交通車輛專業(yè)英語課件：Constructure of AC Electric Locomotive

ConstructureofACElectricLocomotiveRailwayVehicleEnglishPart1:ReadingMaterialFig.2-3PartsofanACelectriclocomotivePart1:ReadingMaterialTheFig.2-3showsanACelectriclocomotive,i.e.,alocomotivecollectingACpowerfromanoverheadline.Thecurrentpassesdirectlyfromthepantograph(orshoe)tothemainandauxiliaryinverters.Part1:ReadingMaterial1.ElectronicControls

Almosteverypartofthemodernlocomotive’sequipmenthassomeformofelectroniccontrol.Theyareusuallycollectedinacontrolcubiclenearthecabforeasyaccess.Thecontrolswillusuallyincludeamaintenancemanagementsystemofsomesortwhichcanbeusedtodownloaddatatoaportableorhand-heldcomputer.2.Pinion/Gear

Thetractionmotordrivestheaxlethroughareductiongearofarangebetween3to1(freight)and4to1(passenger).Part1:ReadingMaterial3.AsynchronousMotor

ModerntractionmotortypeusethreephaseACelectricalsupplyandnowthefavoureddesignformoderntraintractionsystemscanbeusedonDCandACelectrifiedrailwayswithsuitablecontrolelectronicsandonelectriclocomotives.4.AxleBrush

Themeansbywhichthepowersupplycircuitiscompletedwiththesubstationoncepowerhasbeendrawnonthelocomotive.Currentcollectedfromtheoverheadlineorthirdrailisreturnedviatheaxlebrushandoneoftherunningrails.Part1:ReadingMaterial5.Battery

Alltrainsareprovidedwithabatterytoprovidestart-upcurrentandforsupplyingessentialcircuits,suchasemergencylighting,whenthelinesupplyfails.ThebatteryisusuallyconnectedacrosstheDCcontrolsupplycircuit.6.CircuitBreaker

Anelectrictrainisalmostalwaysprovidedwithsomesortofcircuitbreakertoisolatethepowersupplywhenthereisafault,orformaintenance.OnACsystemstheyareusuallyontheroofnearthepantograph.Therearetwotypes—theairblastcircuitbreakerandthevacuumcircuitbreakerorVCB.Theairorvacuumpartisusedtoextinguishtheairwhichoccursasthetwotipsofthecircuitbreakerareopened.Part1:ReadingMaterial7.Converter

Generictermforanysolidstateelectronicsystemforconvertingalternatingcurrenttodirectcurrentorviceversaisconverter.WhereanACsupplyhastobeconvertedtoDCitiscalledarectifierandwhereDCisconvertedtoACitiscalledaninverter.ThewordoriginatedintheUSbutisnowcommonelsewhere.8.CoolingFansTokeepthethyristorsandotherelectronicpowersystemscool,theinteriorofamodernlocomotiveisequippedwithanairmanagementsystem,electronicallycontrolledtokeepallsystemsoperatingatthecorrecttemperature.Thefansarepoweredbyanauxiliaryinverterproducing3-phaseACatabout400V.Part1:ReadingMaterial9.DCLinkUsedonmodemelectronicpowersystemsbetweenthesinglephaserectifierandthe3-phaseinverter,itiseasiertoconvertthesinglephaseACfromtheoverheadlinetothe3-phaserequiredforthemotorsbyrectifyingittoDCandtheninvertingtheDCto3-phaseAC.10.Inverter

Electronicpowerdevicemountedontrainstoprovidealternatingcurrentfromdirectcurrent.PopularnowadaysforDCrailwaystoallowthree-phasedriveorforauxiliarysupplieswhichneedanACsupply.Part1:ReadingMaterial11.LineBreaker

Electro-mechanicalswitchinatractionmotorpowercircuitisusedtoactivateordisablethecircuit.Itisnormallyclosedtostartthetrainandremainsclosedallthetimepowerisrequired.Itisopenedbyacommandfromthedrivingcontroller,no-voltsdetected,overloaddetectedand(wererequired)wheelspinorslidedetected.Itislinkedtotheoverloadandno-voltcontrolcircuitssothatitfunctionsasaprotectivecircuitbreaker.12.MasterController

Driver'spowercontroldeviceislocatedinthecab.Thedrivermovesthehandleofthemastercontrollertoapplyorreducepowertothelocomotiveortrain.Part1:ReadingMaterial13.MotorBlowers

Tractionmotorsonelectriclocomotivesgetveryhotand,tokeeptheirtemperatureatareasonablelevelforlongperiodsofhardwork,theyareusuallyfittedwithelectricfanscalledmotorblowers.Onamodernlocomotive,theyarepoweredbyanauxiliary3-phaseACsupplyofaround400Vsuppliedbyanauxiliaryinverter.14.Rectifier

AconverterconsistingofthyristorsanddiodesisusedtoconvertACtoDC.Amodernlocomotivewillusuallyhaveatleasttwo,oneforthepowercircuitsandoneormorefortheauxiliarycircuits.Part1:ReadingMaterial16.SandBox

Locomotivesalwayscarrysandtoassistadhesioninbadrailconditions,andisoftenprovidedonmultipleunittraintoo.17.SynchronousMotor

Tractionmotorwherethefieldcoilsaremountedonthedriveshaftandthearmaturecoilsinthehousing,theinverseofnormalpractice.Thisisasingle-phasemachinecontrolledbysimpleinverter.Nowsupersededbytheasynchronousmotor.Part1:ReadingMaterial18.Transformer

Asetofwindingswithamagneticcoreisusedtostepdownorstepupavoltagefromoneleveltoanother.Thevoltagedifferencesaredeterminedbytheproportionofwindingsontheinputsidecomparedwiththeproportionontheoutputside.AnessentialrequirementforlocomotivesandtrainsusingACpower,wherethelinevoltagehastobesteppeddownbeforeusedonthetrain.19.Pantographs

Currentiscollectedfromoverheadlinesbypantographs,asshowninFig.2-4.Pantographsareeasyintermsofisolation—youjustlowerthepantolosethepowersupplytothevehicle.However,itiscomplicatedtooperate.Part1:ReadingMaterial

Sincethepantographisusuallythesinglepointpowercontactforthelocomotiveorpowercar,itmustmaintaingoodcontactunderallrunningconditions.Thehigherthespeed,themoredifficultthemaintenanceofgoodcontact.Wehavealreadymentionedtheproblem(above)ofawavebeingformedinthewirebyapantographmovingathighspeed.Fig.2-4PantographPart1:ReadingMaterialPantographcontactismaintainedeitherbyspringorairpressure.Compressedairpressureispreferredforhigh-speedoperation.Thepantographisconnectedtoapistoninacylinderandairpressureinthecylindermaintainsthepantographintheraisedcondition.RailwayVehicleEnglishPart2：VocabularyPart2:Vocabularythyristor半導體閘流管sandbox砂箱transformer變壓器axlebrush軸刷pantograph受電弓vacuumcircuitbreaker(VCB)真空斷路器asynchronousmotor異步電動機auxiliaryinverter逆變器electroniccontrol電氣控制Part3:CommentariesforLongDifficultSentencesRailwayVehicleEnglishPart3:CommentariesforLongDifficultSentences123Currentcollectedfromtheoverheadlineorthirdrailisreturnedviatheaxlebrushandoneoftherunningrails.

從架空線路或第三軌道收集的電流通過軸刷和其中一個運行軌道返回。Tractionmotorwherethefieldcoilsaremountedonthedriveshaftandthearmaturecoilsinthehousing,theinverseofnormalpractice.

牽引電機的磁場線圈安裝在傳動軸上，電樞線圈安裝在外殼上，這與正常的做法相反。Tokeepthethyristorsandotherelectronicpowersystemscool,theinteriorofamodernlocomotiveisequippedwithanairmanagementsystem,electronicallycontrolledtokeepallsystemsoperatingatthecorrecttemperature.為了保持晶閘管和其他電子電力系統(tǒng)的冷卻，現代機車的內部配備了空氣管理系統(tǒng)，由電子控制，以保持所有系統(tǒng)在正確的溫度下運行。Part3:CommentariesforLongDifficultSentences45Theaircompressorisrequiredtoprovideaconstantsupplyofcompressedairforthelocomotiveandtrainbrakes.空氣壓縮機需要為機車和列車的制動器提供持續(xù)的壓縮空氣供應。

Sincethepantographisusuallythesinglepointpowercontactforthelocomotiveorpowercar,itmustmaintaingoodcontactunderallrunningconditions.由于受電弓通常是機車或動力車的單點電源接觸點，因此在所有運行條件下都必須保持良好的接觸RailwayVehicleEnglishPart4:ExerciseandActivityPart4:ExerciseandActivityDirections：Explainthemeaningsandfunctionsofthefollow